Radiometrically dated speleothem records of Terminations IV and V and linkages to the North Atlantic

Paleoclimate archives tied to accurate and precise chronologies are crucial for developing a dynamical understanding of the causes and nature of Quaternary glacial terminations [1]. While numerous well-dated archives provide good chronological control through Terminations I and II, there is presently a lack of well-dated records spanning earlier terminations. A notable exception to this is a suite of remarkably well-dated Chinese speleothems that have been used to date the commencement of each termination over the past 640 kyr [2,3]. This has been achieved by correlating weak Asian Monsoon anomalies as captured by speleothem oxygen isotope signals with terminal Heinrich events in the North Atlantic. While this approach is well-suited to testing orbital hypothesis by comparing the timing of termination commencement with insolation metrics, it only provides precise age control at the beginning of each termination. This precludes assessment of the progression of climatic changes over the full course of the termination, and the timing at which full interglacial conditions are reached. Here we present a composite speleothem record spanning glacial terminations IV and V from the Antro del Corchia cave system located on the western coast of central Italy. This record is anchored to a uranium-thorium based chronology and contains numerous proxies representing both local and regional climate, including Δ47-based temperature data derived from a pool carbonate formed under very slow degassing conditions. By taking advantage of established links between speleothem proxies from this cave site and marine proxies from the North Atlantic, we fix the marine sediment data to a radiometric age scale. This allows us to constrain the timing of ocean circulation and SST changes occurring in the North Atlantic throughout the duration of Terminations IV and V, and compare these with terrestrial temperatures in central Italy. © The Authors.

Keywords

Records management, Quaternary period, Glaciers, China, Hypothesis, Climatic change, Caves, Italy, Sediments

Citation

Pollard, T., Drysdale, R., Woodhead, J., Edwards, R. L., Hellstrom, J., Cheng, H., Dux, F., Daëron, M., Li, X., Wong, H., Couchoud, I., Regattieri, E., Zanchetta, G., & Isola, I. (2019). Radiometrically dated speleothem records of Terminations IV and V and linkages to the North Atlantic. Poster presented to the 20th INQUA Congress 25th - 31st July 2019, Dublin, Ireland. Retrieved from: https://virtual.oxfordabstracts.com/#/event/public/574/submission/1569